viessmann 050-w and viessmann generally

[Deleted member 131795]

hello!

while saving up for a new plumbing and heating installation for my new one bedroom flat, i did a lot of research on different boilers and systems, sought some advice, and settled on a viessmann vitodens 050-w, seems to offer a lot in terms of features and reliability, offers good value etc.

researched the weather compensation thing and this is definitely the route i'd like to go. however, a viessmann installer that quoted me yesterday said the 050-w doesn't have a timer function. i couldn't believe this would be possible on a £1k boiler, so checked with viessmann and right enough, it is not included on this model; i would need a 100-w to get timer functionality!

this annoys me for a number of reasons, mostly because a simple timer is a software function that cost viessmann nothing and it probably cost them more to disable the function at the design stage; i think this is a case of simply hampering basic functionality at the low end to make the next model up seem more desirable. you might say, well, that's business. but also, viessmann push weather compensation, it's kind of what they are all about, and this itself is part of a move away from room thermostats, trvs, on / off controls etc, yet viessmann say that to get a timer i'd need a third party control. viessmann don't even make a control that is compatible with the 050-w that has opentherm, so it would need to be an eph or similar.

the reason i want a timer is simply to get a setback feature for night time, maybe drop it 2 or so degrees when i go to bed. i don't want to set programs or holidays or heat the flat differently at the weekend. it just seems mental that i have to get a separate timer / room thermostat to get this.

surely the one thing you want if you are using weather compensation is a setback feature?!

can anyone offer any help, opinions or thoughts on this?

thanks!

 

[Chuck]

In my opinion, weather compensation should be a supplement, not an alternative, to a programmable room thermostat. This is particularly the case in a flat where the losses through the walls/floor/ceiling will vary depending on what the occupants of the neighbouring flats are doing.

 

[Deleted member 131795]

In my opinion, weather compensation should be a supplement, not an alternative, to a programmable room thermostat. This is particularly the case in a flat where the losses through the walls/floor/ceiling will vary depending on what the occupants of the neighbouring flats are doing.

interesting, thanks. this is the view that most in the uk seem to share.

the other view, which is apparent on the european esp german forums; if you have a modulating boiler with weather comp, then you shouldn't use setback / timer / room thermostats at all. setback is for on/off systems. if you have weather comp you do not need setback, end of story. it's counterproductive to the logic of a modulating boiler. just let it modulate and leave it on 24/7.

i agree it's hard to get your head around the idea that something being on all the time, even at night when asleep, is going to be more efficient / cheaper. and there is also the fact that in these times, there is unfortunately, for most people, some guilt around consuming too much energy and 'leaving something on 24/7' is loosely synonymous with consuming too much energy.

then there's the counter-argument; our buildings are not nearly as well insulated as european apartments, we have way more heat loss, etc. but taking into account thermal mass and recovery times after setback, and having to heat the contents up again, you're apparently still no better off than just leaving on 24/7.

it's a debate that has been going on for over 15 years. i find it quite interesting. i'm likely going to just install the boiler with weather comp and no additional controls, and set and forget, maybe for the first year. see how it pans out.

 

[gmartine]

Although not strictly on/off you can set temp/timing controls with the ViCare app which you can use with the new ViCare room stat or other compatible. That'll give you adequate control for a modest further outlay.

Viessmann ViCare Wireless Thermostat (Modulating) ZK05991

Viessmann have developed the ViCare wireless thermostat to enable the ability to adjust your heating and hot water from anywhere around the world. Use the ViCare app from any smart device to ensure your home is powered with smart heating.

golita.co.uk

 

[Deleted member 131795]

Although not strictly on/off you can set temp/timing controls with the ViCare app which you can use with the new ViCare room stat or other compatible. That'll give you adequate control for a modest further outlay.

as far as i'm aware you can't set timing using the vicare app with the 050-w.

also, that room stat isn't compatible with weather compensation.

 

[gmartine]

The app and the boiler on it's own no but with addition of the smart room stat you should be able to.

As per the above discussion the stat not being compatble with WC makes sense.

 

[Desktop987456]

Even the 100-w heat only boiler doesn't have timer.

Does setback apply to heat only boiler since they are also on/off devices with modulating flame?

 

[Knappers]

I struggle a bit with this topic too.
Well insulated buildings with UFH - sure run it 24-7.
Rads by their nature are comparatively good at heating a space fairly quickly and have very little in terms of thermal mass.
Rads work best with thermostats and timers. I think a combination of weather comp and optimisation is best.
Some controllers do this but it's very difficult to find out how they all work with manufacturers being very focused on the gimmicky side of smart controls and giving very little meat on the actual heating command side of things.
I can with great confidence affirm tho that running wet radiator central heating on a timer and stat will be MUCH more efficient than running continuously, provided you have decent chunks of the day that it can be 'off', your not retired, in the house all day and running heating at 25deg.
I also believe that the efficiency gains of weather comp and optimisation are grossly understated if you factor in that a well balanced and smoothed out heating cycle should allow you to reduce the heating setpoint and maintain the same comfort level - possibly increasing efficiency an extra 10% or so.
That's what I think anyway!

 

[Deleted member 131795]

I struggle a bit with this topic too.
Well insulated buildings with UFH - sure run it 24-7.
Rads by their nature are comparatively good at heating a space fairly quickly and have very little in terms of thermal mass.
Rads work best with thermostats and timers. I think a combination of weather comp and optimisation is best.
Some controllers do this but it's very difficult to find out how they all work with manufacturers being very focused on the gimmicky side of smart controls and giving very little meat on the actual heating command side of things.
I can with great confidence affirm tho that running wet radiator central heating on a timer and stat will be MUCH more efficient than running continuously, provided you have decent chunks of the day that it can be 'off', your not retired, in the house all day and running heating at 25deg.
I also believe that the efficiency gains of weather comp and optimisation are grossly understated if you factor in that a well balanced and smoothed out heating cycle should allow you to reduce the heating setpoint and maintain the same comfort level - possibly increasing efficiency an extra 10% or so.
That's what I think anyway!

thanks for your input.

i'm struggling with it too! but from what i understand, viessmann boilers do weather compensation very well.

there is some really good discussion on heatinghelp forum, for example the following:

(i had to remove the link because links on forums are more harmful than capitalism and war)

my flat is a 1980s build, reasonably well insulated, cavity walls, full loft installation, double glazed, etc. i work from home, and don't go away for long periods of time. i like to keep the temperature around 18C all the time.

it seems, particularly in europe (i'm aware the properties there are better insulated) the always on weather compensation approach is far more prevalent. keep it comfortable. however, this doesn't really align with the uk views on the subject.

like you say, a lot of it comes down to the circumstances, and sure in many cases a timer will be required. i think the only way is to do your own tests and see what works out best over the course of a season or year. it's probably quite difficult. but i like the concept of 24/7 with no timers / controls / thermostats. it makes sense to me. certainly far better than manual control on it's own; this whole 'ooh i feel chilly, let's put the heating on' seems slightly whimsical and brit-like (stupid, ultimately) - i've been sat in a 30C room and felt the same comfort as when the room was 20C on many occasions. similarly, when using on/off controls, i've felt chilly when the temp drops slightly below the desired temperature, even though that temperature was around 19C!

surely what we want is comfort, not knee jerk adjustments that will result in comfort only a third of the time.

i get what you're saying. but i think well a well configured 24/7 weather compensated system is the way forward and, sure, it might be that it doesn't always result in an outright cheaper fuel bill, but it will be a better / more comfortable experience.

(although the germans argue it's cheaper)

 

[Knappers]

I'm pretty sure viessmann with weather comp will work well with 3rd party control but avoid anything with opentherm, you just want on/off control (with setback option at 12°C-15°C imo).
Avoid viessmann vicare stat as it won't work with that and weather comp (just one or the other)

 

[Knappers]

Personally I'm not a fan of European boilers.
British boilers work best for British situations.
Great quality boiler with great installer incentives but parts and aftercare are miles from the likes of Worcester and Baxi.
In my mind it's like buying a household appliance with a euro plug designed to work on 60hz - just not quite right for us

 

[Deleted member 131795]

I'm pretty sure viessmann with weather comp will work well with 3rd party control but avoid anything with opentherm, you just want on/off control (with setback option at 12°C-15°C imo).
Avoid viessmann vicare stat as it won't work with that and weather comp (just one or the other)

dammit i wanna go without the additional controls altogether if possible!

most installers just bundle in an EPH C4 with these, which is a decent controller. it's opentherm but you can use on/off too.

yeah, aware of the incompatibility with weather comp and that device.

 

[Deleted member 131795]

Personally I'm not a fan of European boilers.
British boilers work best for British situations.
Great quality boiler with great installer incentives but parts and aftercare are miles from the likes of Worcester and Baxi.
In my mind it's like buying a household appliance with a euro plug designed to work on 60hz - just not quite right for us

interesting perspective.

yeah, earlier in the year i looked at wb 2000 and 4000. a few weeks ago they brought out the 1000 which is their new and first ever 'budget boiler' - any thoughts on that?

from all my research the feeling i got was the they are less reliable than viessman though?

i was also quite interested in the main eco compact for a while.

 

[Knappers]

I haven't gone through the 1000 yet but I like the 4000 (not so much the 2000).
Main is a budget Baxi but with no rear piping option.
I like WB with bosch easy control on a combi with one zone.
Baxi/main with opentherm controls is another option but only have a 5:1 modulation ratio opposed to 10:1 on WB (min around 6kw vs 3kw ish on worcester) minimum matters!

With more than one piped heating zone I think the best option is probably a wired weather comp sensor and 230v switching controls with setback temp between 12&15degc (baxi do an in-flue weather comp sensor which is nice)

There's no doubt Viessmann are nice boilers but with the service network of WB if a slight difference in reliability exists, its more than compensated for!

 

[Knappers]

I've recently started to question the UV stability of some of the baxi plastics too but it's just a feeling....tbc